This invention relates to minimally invasive surgery and blood vessel harvesting.
Coronary bypass surgery is a well-known treatment for patients suffering from severe coronary artery disease. Bypass surgery involves implantation of a length of tubing, referred to as a graft, around a clogged segment of a coronary artery. The tube may be a synthetic material, a length of vein or artery from a donor, or a length of vein or artery harvested from the person undergoing the bypass operation. It is greatly preferred to use a length of vein or artery from the person undergoing the bypass operation, and the graft harvested from the patient is referred to as an autologous graft. Several blood vessels are commonly harvested for use as autologous grafts, including the saphenous vein, the internal mammary artery, and the inferior epigastric artery. Among the several blood vessels used for bypass grafts, the saphenous vein has been commonly used due to its ease of harvesting. The saphenous vein""s superficial location along the inside of the leg (the saphenous vein can be easily felt under the skin, between the groin and the knee) makes it easy to locate and remove from the leg. The saphenous vein is well suited for use as a graft because it is about the same size (or a bit larger) as the coronary arteries. The saphenous vein is also somewhat redundant, and other veins in the leg readily take up the venous blood flow that normally flows through the saphenous vein, so that its removal from the leg does not seriously hamper blood supply in the leg. Some of the drawbacks to use of the saphenous vein are 1) unavailability (e.g. from prior vein stripping), 2) suboptimal long term patency rates and 3) its harvesting usually requires a sizable open wound along the entire length of the leg. We have previously suggested a minimally invasive method for harvesting the saphenous vein to avoid the large wound in our issued patent, Methods And Devices For Blood Vessel Harvesting, U.S. Pat. No. 5,601,581 (Feb. 11, 1997).
The internal mammary artery and inferior epigastric artery are suitable for use a coronary artery bypass grafts for several reasons. Because they are arteries and not veins, they are anatomically better suited to withstand the pressure of the arterial vasculature since they are arteries in the first place. They are about the same diameter as the coronary arteries. They tend to last longer without stenosis, clotting, aneurysm or other failures which require yet another intervention. For left-side cardiac bypass, the internal mammary artery is a preferable graft to the saphenous vein because it has been shown to stay open and unclogged longer. The inferior epigastric artery also performs well as a bypass graft, providing long term patency similar to that of the internal mammary artery.
The method described below is primarily concerned with harvesting the inferior epigastric artery. The location of the inferior epigastric arteries within the body makes them more difficult than the saphenous vein to harvest via the traditional open surgical approach. This traditional method entails increased operating time, and results in more invasive surgery. The inferior epigastric artery is located adjacent to and within the rectus abdominus muscle. It extends upwardly from the external iliac artery (just above the inguinal ligament, near the crease of the thigh), extends upwardly under the rectus muscle, and enters the rectus muscle. In many cases, it courses for some length through the rectus muscle. To harvest the inferior epigastric artery in the traditional method, the surgeon must make a long incision from the ribs to the lower abdomen. The skin, pre-peritoneal fat and rectus sheath must be incised, separated and retracted to provide access to the artery. The artery is removed from the body by ligating and dividing the side branches, then ligating the inferior epigastric artery both at its origin near the iliac artery and near its distal end in the upper abdomen, and dividing and removing the artery. This technique is illustrated in detail in Mills, et al., Techniques For Use Of The Inferior Epigastric Artery As A Coronary Bypass Graft, 51 Ann. Thoracic Surg. 208 (1991).
The inferior epigastric artery harvested according the method disclosed below may be used as a graft in coronary bypass surgery in place of the saphenous vein. It may also be used in other bypass operations such as the femoral-popliteal bypass in the leg. The harvested artery may also be used to provide a graft for muscle transfers performed by plastic surgeons to rebuild damaged parts of the body. Thus the method of harvesting the inferior epigastric artery may be used to reduce the trauma of the harvesting operation for a number of graft applications.
The applicants have discovered a laparoscopic technique for harvesting the inferior epigastric artery and removing it from the body. The harvested inferior epigastric artery may be used as a bypass graft in a coronary bypass operation. The method avoids the open surgery and the large incision previously required for harvest of the inferior epigastric artery. This is advantageous because the artery is usually harvested for immediate use in the patient""s own bypass operation. The method is also very quick and much less traumatic than the current open surgical method of harvest.